Well, aren't some people just heart-warmingly lovely? We were tending a couple of family graves a few months ago and one of the gardeners who was working on the war graves was kind enough to lend us a couple of watering cans and then came over to impart some words of wisdom...
The secret to those pristinely white war gravestones is... da da da... washing-up liquid!! Buy the cheap stuff and paint it on really thick with a brush. Wait 5 days or so until it has dried and cracked and then brush it off with a dry brush. Repeat 5 or 6 times a year. Apparently after a year of doing this our gravestones (which were in an unspeakable state despite a lot of effort!) would be looking nearly-new and the lettering wouldn't be affected. Well, it sounded easy, so we tried it... and the proof is in the pictures...
Before:
And yet another tip from that kind gardener... When planting flowers, instead of pouring water into the hole, use lemonade! All that fizz provides wonderful aeration - better than plant food, and a lot cheaper too! Lemonade can also be used in vases for indoor flowers, or use coloured fizzy pop for added decoration!